USPSTF Research Plan CVD No Risk Factors

March 18, 2015

Michael LeFevre, MD, MSPH
c/o USPSTF
540 Gaither Road
Rockville, MD 20850

Re: USPSTF DRAFT Research Plan: Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease Prevention in Persons without Known Risk Factors

Dear Dr. Cosby:

The Academy of Nutrition and Dietetics (the "Academy"), formerly the American Dietetic Association, is pleased to comment on the USPSTF DRAFT Research Plan: Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease (CVD) Prevention in Persons without Known Risk Factors. The Academy is the world's largest organization of food and nutrition professionals, with more than 75,000 members comprised of registered dietitians (RDNs), dietetic technicians, registered, and advanced-degree nutritionists. Every day we work with Americans in all walks of life--from birth through old age--providing nutrition care. We are committed to improving the nation’s health through food and nutrition and providing medical nutrition therapy (MNT), and other evidence-based nutrition counseling services that meet the health needs of all citizens.

Section I ("Do you have any questions about Proposed Analytic Framework")

Definition of "behavioral counseling" in search terms

Since 1996, the USPSTF and affiliated researchers have undertaken a series of evidence reviews and systematic evidence updates analyzing available studies related to dietary interventions and counseling to promote a healthy diet. These reviews identify intensity of intervention (minutes in a session) as the most significant factor; after intensity, the most consistent factors of effective interventions are the specialized qualifications of the provider and the provision of services at a venue being outside the primary care setting. The largest changes in diet come from interventions conducted by a registered dietitian nutritionist or other specially trained practitioner conducted outside of the primary care setting. Thus, search terms used in the literature search are important to make sure that applicable dietary interventions are included. Some may be referred to in the literature using other terms. Therefore we suggest that search terms include "medical nutrition therapy" and "dietary counseling," including any counseling provided by "dietitians," "dieticians," "nutritionists," or that includes a dietitian on the health care intervention team. We encourage USPSTF to incorporate studies and recommendations from recently published evidence reviews and guidelines and to differentiate protocol-based behavioral counseling from more complex individualized Medical Nutrition Therapy, the latter of which is a recognized necessary and effective component of care for individuals with multiple chronic conditions (including prevention of CVD).

Section II ("Do you have any questions about Proposed Key Questions to Be Systematically Reviewed")

(Relevant to all questions and Proposed Research Approach)

The USPSTF has repeatedly recommended intensive behavioral [dietary] counseling for various disease states and conditions with what appeared to be clear recommendations that primary care providers are able to refer patients to RDNs and other qualified experts outside of the primary care setting to provide and deliver these services. Frustratingly, despite the USPSTF's intention for its recommendations to be primary care relevant and to include referral, CMS indicates to us that USPSTF recommendations are only "for primary care clinicians," in part because that is who comprises Task Force members. As a result, the Task Force's recommendations for some of the nation's most pressing problems cannot be implemented in Medicare or public and private insurance that follows CMS’s lead. The Academy respectfully requests a meeting at your earliest convenience to discuss these hurdles in implementing Task Force recommendations.

As noted above, the use of "primary care behavioral counseling interventions" related to each of the four proposed key questions poses multiple problems, both for interpretation of research findings by the USPSTF evidence review and for the implications of published USPSTF findings. Primary care providers are often limited in their time, training, and skills to conduct the medium or high-intensity interventions that are scientifically proved to be the most effective in producing the largest, most lasting results. It is both cost-effective and efficient to have primary care provider-driven referrals of patients with risk factors for CVD to practitioners skilled in conducting dietary interventions who practice both inside and outside of primary care settings.

Thus, the Academy asks that the USPSTF either revise wording to refer to "primary care relevant" (i.e., referable from primary care) behavioral interventions or (2) an additional four proposed research questions asking about behavioral interventions referable from primary care to specialists, such as RDNs. We note that the first option does not differentiate outcomes provided by professionals who may differ in time and expertise. Therefore, the second option appears preferable. Alternatively, if the interventions are examined as primary care relevant within the same questions, the Academy urges reviewers to make note of differences in outcome based on provider and/or setting. Such a change would comport with the "settings" section of the Proposed Research Approach, does indicate that studies included are "Conducted in or recruited from primary care or a health care system or could feasibly be implemented in or referred from primary care."

The key questions comprising the analytical framework raise potential analytical and research concerns, because in many primary care settings "behavioral counseling" is used to refer work by "behaviorists" in the medical home model, who are usually licensed mental health professionals. Given the success of registered dietitian nutritionists (RDNs) in behavioral counseling interventions for a healthful diet, the Academy suggests that a more appropriate target question would refer to "behavior-focused counseling," with search terms including those in the paragraph above.

Intensity and duration of interventions as important and somewhat distinct factors

(Relevant to all questions and Proposed Research Approach)

Description of interventions is important for USPSTF's evaluation of results, as noted in the USPSTF recommendation regarding behavioral counseling for cardiovascular disease prevention among adults with known risk factors and numerous other reports and analyses of research. In short, intensity of interventions often has strong influence on outcomes.

The Academy supports the identification of comparison groups in this USPSTF research plan as no intervention, minimal intervention, and attention control.

It is important that the USPSTF not group together all interventions in conclusions. That is, according to criteria in the draft research plan, outcomes from a one-time half-hour group class could be considered equally alongside a 12-week program of weekly hour-long behavioral sessions that also includes supervised weekly exercise. Past reports have made note of how differences in intensity influence results, for example noting that low intensity interventions are ineffective for an outcome for which a medium or high intensity intervention is effective. If, as would be expected given other analyses and reviews, more intense interventions are more effective relevant to the research questions posed here, this has important implications for quality of patient care that is supported, and for the opportunity for RDNs to do the more intense interventions we are trained to provide.

We note that for these purposes, intensity of interventions has relatively standard definitions related to number of sessions and frequency. Variations could include duration of sessions and the time period over which an intervention extends.

We further note that the stipulated timing of outcome assessment for questions 1 through 3 is defined as ≥6 months from baseline, which is desirable in looking at longer-term outcomes. While this is addressing longer-term health outcomes, which are crucial to actual effectiveness, depending on the length of intervention and individual’s circumstances, this could miss effects seen in shorter time frames that have been lost by six months. We suggest including two time frames: <6 months (or perhaps 3-6 months to avoid only very short-term effects) and separately, ≥6 months from baseline. If research shows short-term but not long-term effects, this allows further investigation (another review) to identify how short-term success can be supported to create long-term benefits. Therefore, just as with intensity of intervention, there should be some plan built into this review to allow for recognition of potentially different outcomes among short- versus long-term interventions.

Intervention Outcome Measures

Relevant to all questions and Proposed Research Approach

A crucial point here is that the research and contextual questions address how we reduce CVD risk in people without known risk factors. Therefore, relying on changes in standard risk factors may show little impact of intervention, if the risk factors were not elevated to begin with. It is not clear whether the list of intermediate CVD risk factor outcomes is complete as noted in the research plan as presented, or is meant to show examples of how risk will be defined. Certainly, the outcomes of blood pressure, lipids, glucose and weight are standard and important. If this list is a limiting list, such that other outcomes relevant to cardiovascular risk cannot be considered, then we recommend expanding the list of risk factor outcomes.

Specifically:

  • Since random glucose does not represent ongoing blood sugar control, A1C is another measure valuable in addition to glucose level to assess this aspect of risk. For people who do not have diabetes (identified as an exclusion criteria in this research plan), if measures of insulin sensitivity or resistance are available in a study, this is highly relevant to the goal of cardiovascular disease prevention, because insulin resistance is tied to metabolic syndrome, which is known to identify people at risk of cardiovascular disease.
  • It is assumed that “lipids” refers to LDL and HDL cholesterol as well as serum triglycerides.
  • The Academy suggests reduction in Metabolic Syndrome as another appropriate indicator of CVD risk.
  • Rather than referring to weight/body mass, the Academy suggests an outcome of weight/body mass index (BMI). (BMI and body mass are not the same things.)
  • In addition to weight/body mass index, waist circumference is increasingly identified in research as addressing an aspect of adiposity-related risk that is not necessarily captured by (and is sometimes more responsive to intervention) than a measure like body mass index (BMI).
  • Other factors identified in the 2013 ACC/AHA Guideline on Assessment of Cardiovascular Risk as factors that can inform treatment decisions: hs-CRP (high-sensitivity C-reactive protein), CAC (coronary artery calcium) score, ABI (ankle-brachial index), 10-year CVD risk score, and 30-year or lifetime CVD risk score.

It is possible that improvements in eating and exercise behaviors will first show improvements in some of these markers, such as CRP-measured inflammation, among people relevant to this USPSTF research plan who are not originally identified as at CVD risk.

Section III ("Do you have any questions about the Proposed Research Approach")

In the "[c]ondition definition," the Academy recommends a change to include "adherence to cardio-protective dietary patterns" and the addition of "nuts and non-tropical oils" to list of foods in parentheses.

The Academy recommends that, in addition to the outcomes currently listed in the draft research plan (i.e., intermediate, behavioral, and health outcomes), the USPSTF also include quality of life as an outcome. The Academy notes that CMS identifies quality of life as a component of its "Triple Aim" to be monitored and achieved. Quality life data, however, should be included in the systematic review only if it is collected through validated instruments.

Although the USPSTF recommendations were not originally intended to make coverage decisions, they have become paramount to coverage in resent legislation and regulations. Given the reality that USPSTF recommendations are determinants of insurance coverage through Medicare, Medicaid, and Essential Health Benefits, it will be important to identify key intervention characteristics that influence the effectiveness of the interventions to understand their impact on outcomes. Specific intervention characteristics to identify and assess include the intensity of the intervention (i.e., frequency of sessions, length of sessions, and length of commitment) and the types and roles of practitioners involved in the intervention. For example, a portion of the review could determine the extent to which the presence of dietitians in the interdisciplinary team impacts effectiveness of the intervention, and whether interventions conducted solely by primary care physicians are as effective as those with an interdisciplinary team. In short, the research plan should help identify what practitioners make particular interventions clinically feasible and cost effective in promoting a healthy diet and physical activity for CVD prevention in persons with known risk factors, particularly when the behavioral counseling is highly intensive. It is critical that the USPSTF identify and compare the theoretical models underlying the reviewed interventions to allow an "apples to apples" comparative effectiveness analysis.

The Academy queries whether cost-effectiveness of intervention should be included in the USPSTF review of evidence. Even if primary care-provided and primary care-referred behavioral counseling showed equally effective outcomes through equally intensive interventions, an important question for policy implications and for RDNs is the cost-effectiveness of interventions. Since USPSTF exclusion criteria already remove programs such as worksite wellness or church-based programs from consideration, one aspect of the value RDN-provided interventions can offer goes beyond the quality of the intervention to examine the cost-effectiveness compared to care provide by primary care providers themselves. Our Academy experts are currently evaluating results regarding cost effectiveness of MNT in weight management (which would be a group included in this USPSTF review) and we would be pleased to report these results to you when they conclude their work.

Lastly, under the criterion "Study designs," the Academy notes its support of the use of multiple study designs, including systematic reviews, randomized controlled trials, clinical controlled trials, and both comparative cohort and population-based case-control studies.

We recognize the complexity of this topic and offer our assistance and evidence analysis as USPSTF begins its evidence review. Please contact either Jeanne Blankenship at 202-775-8277 ext. 1730 or by email at jblankenship@eatright.org or Pepin Tuma at 202-775-8277 ext. 6001 or by email at ptuma@eatright.org with any questions or requests for additional information.


1 Medical nutrition therapy (MNT) is an evidence‐based application of the Nutrition Care Process. According the Academy's definition, the provision of MNT (to a patient/client) may include one or more of the following: nutrition assessment/ re‐assessment, nutrition diagnosis, nutrition intervention and nutrition monitoring and evaluation that typically results in the prevention, delay or management of diseases and/or conditions. [Academy of Nutrition and Dietetics. Definition of Terms List. Accessed December, 17 2012.] The term MNT is sometimes used interchangeably with, but is sometimes considered different from, nutrition counseling in health insurance plans. Further, the Academy’s definition of MNT is broader than the definition of MNT in the Social Security Act (42 U.S.C. 1395(vv)(1)).